Listen closely, I'm going to teach you to walk.
1: Unless money is no object, you should slow your roll. At your stage, practice is EVERYTHING. Save your money for ammo. The 870 is a fine gun for an entry level piece. Contrary to popular opinion, I would get the 12 unless you are of especially small stature due to ammunition availability in various loadings. Other quality beginner options are made by Stoeger, Benelli (pump) and Mossberg. Get a field gun, not a specialty slug gun. Shoot the hell out of it at trap/skeet/sporting clays with 1 oz target loads. Go into this with no pride, seeking shooters who are willing to help a newbie. There will be plenty. Ignore anyone that blows you off. Once you feel you have some proficiency, hunt you some squirrels, rabbits, whatever birds you have access to. Build your general hunting/stalking/spotting skills. Moving and sitting quietly in the woods is an art, it takes time to develop. Your 870 will throw conventional "rifled" slugs decently through an open choked, bead sighted "bird" barrel to 50 yards or so. Stay with 2 3/4" slugs in the lighter weight. Shoot them with a slip on recoil pad. Recoil will be manageable. This should be your goal first year, harvest an antlerless deer within 50 yards. Consider a big buck strictly a target of opportunity. You can always upgrade to a proper slug gun as your proficiency and hunting opportunities allow.
2: Acquire a .22 rimfire rifle, (and handgun if funding permits). Brand, price point doesn't matter much, this is a tool to build basic proficiency. Shoot the hell out of them.
3: Handguns: Don't plan to hunt with them this year. Start with a full-sized .357 magnum. The Taurus M66 will suit this role, more expensive S&W models will do it with a little more flair and refinement. Your goal is to shoot mostly .38s and some .357s as you work up to them. Shoot the hell out of this. Save the big boomer for next year when you're ready.
4: If funding permits, a pellet rifle with an indoor shooting trap would be a good investment also. You can practice basic marksmanship indoors or backyard for pennies.
5: Work on finding a real flesh and blood mentor. We're happy to help on THR, but with an endeavor as complex as hunting, firearms, fieldcraft, there's only so much information to be had on the internet. This is a better forum for specific questions.
Hope this helps.